How do I flash MMB29P

Sorry guys, I have been out of the loop with the Nexus 6p. I'm slightly new to the device. I am currently on MMB29M stock and rooted. I want to flash MMB29P, but I do no have a computer with a working adb. Where can I find a zip for stock MMB29P? Can I simply flash the new build with TWRP or does it have to be done with faceted images through adb? Also do I need to flash a vendor image.

Thanks in advance

Also is there a way I can update without having to wipe data?

Is there any real point for this update and will these "security updates" be happening each month?

Download from this link